Process of producing synthetic sapphires.



A. V. L. VER'NEUIL.

PROCESS 01" PRODUCING SYNTHETIC SAPPHIRES.

APPLIOATION FILED MAY 10, 1910.

Patented-M11128, 1911.

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Be it known that I, AUcns'rn VIo'roR LOUIS VERNEUIL, a citizen of the French Republic, residing at 80 Boulevard St. Germain, Pa'ris, France, have invented certain new and useful Improvements in Processes of Producing Synthetic. sapphires.

The sapphire produced according to th s invention is substantially identical in chemical and hysical properties with, and exactly similar in'appearance' to the blue sapphire found in'nature. I

Various artificial 'ge'ms have already been manufactured synthetically, such as rubies, but up to the present it has been impossible to produce a stone havmg the blue color, and of a nature indistinguishable from that of a natural sapphire.

The apparatusused is the same as that used in the manufacture :of artificial rubies and consists essentially'in a blowpipe producing an oxy-hydrogen flame. v

' an air-tight joint in the top of the'chambe'rural stone.

The materials'whi'ch are used in re-constituting a sapphire are alumina, 'oxid of 'iron and o'xid of titanium, these elements being the elements normally composing the nat- The said constituent materials are powdered, mixed and are caused to fall through the flame on to a column or support of fire clay or other refractory substance where they are fused and form the artificial stone as will be more particularly described below. W

In the accompanying drawings, Figure l is a diagrammatic view of the apparatus used and, Figs. 2-6 show the artificial stone at different stages of theprocess.

The appziratusherein shown is old and is only shown herein for the purpose of more easily describing the present invention. Oxygen is led from a suitable source through the pipe 0 into the chamber A whichlatter contains a receptacle B for the powder forming the composition of the artificial stone; The lower end of this rece tacle B terminates in a sieve like portion 1 composed of wire gauze or similar material of sufliciently fine mesh to prevent the powder falling freely through. The upper end of the receptacle has attached to it a rod passing through A, and provided at its upper end with'a block 0. The block 0 is placed within reach of ahammer D fixed to a rod E pivoted at F, The end of .the rod' E remote from D is Speoiflcationot Letters Patent. I Patented Mf-ar. 28,1911.

row. As the cam engages the end of rod E the hammer D is raised-and when the cam escapes from engagmen't with rod E, the hami'ner'D falls and imparts a shock to the sieve B through the-block C. in this way a small quantity of the powder falls intermittently through the opening in theflower part of the chamber A and through fi'pe' K.

Lighting 01'' other gas fed throng opening H,pa'sses down pipe S and at the mouth of the latter mingles with the oxygen to form the flame which is -inclosecl by a casing M of a refractory substance.

When starting the process, the oxygen is i only fed in a small quantity so that the flame is relatively. cold. The powder falling down onto the fire clay column or support L is accordingly not fused, but merely bakedor fritted, and gradually forms a pyramid l of the shape shown in Fig. 2. As the cone rises,

thefiame acts directly. on the point of'the cone which being of very small mass is fused and the powder as is well known passes from the powdered state instantaneously to the crystalline state at the moment I of fusion, forming a small stalk 2 of crystalline formation, see Fig. 3. The proportion of oxygen in the flame is then graduallv increased andthe powder falling down fuses and forms a bulb of gradually increasing size as shown, 3, 4, 5 in Figs. 4, 5 and 6. The flame is then shut off and the finished -stone allowed to cool. The position of the fire clay column L relative to the flame can i be adjusted by means of the rod N, bracket Q, screwed rod R and handles T and P.

Another, essential feature of my invention resides in the process by means of which we are enabled to produce or reconstitute a sapphire corresponding in color and all its physical and chemical properties with the sapphire as found in nature. The process consists, br'oadly"- speaking, combining alumina, iron andtitanium in the form of oxids. As these substances in a powdered condition fall through the flame, the reaction first consistsin the'reduction of the oxid of iron to a lower oxid, and then in the simul-.

taneous oxidation of the-lower oxid -of iron to the vsesqui-oxid (Fe,0,) and the reduction of the oxid of titanium to a lower oxid. The blue color of thestone thus ultimately obtained is due to the lower oxid of titanium tanium.

Other compounds of aluminium, iron and titanium could be used to form the ingredicuts of the powder besides the OXldS above mentioned, owing to the fact that the flame,

whose temperature during the formation of the stone should be kept at about 1900 C. would reduce any other compounds of these metals which may be employed, to the state of oxids during the passage through the flame, as at this temperature only the oxids of these metals are stable. If other compounds of these metals are used, the proportions in which they enter into the composition of the powder must obviously be correspondingly altered to give the final proportions above mentioned. I wish-it to be understood that it is not absolutely necessary to combine the powder of alumina with the oxids of titanium. and iron which are prepared in the usual manner.

' with the sulfates, carbonates or other compounds or even the pure metals could be used, provided, as already stated, the pro portions are correspondingly varied. If, for

example, the com osition' for making the synthetic sapphire 1S aluminium sulfate, pure iron and the oxid of titanium the proportion of the in redients is 99.74;% of Al (SO,,)3+18H o, 18% cu: Fe and 0.08% of TiO,. V

For any other compounds of the three metallic elements the proportions of the ingredients could be easily calculated by any one versed in the science of chemistry.

Should the ingredients of the composition for making the synthetic sapphire be other than the oxids of the three' metallic elements, a preliminary step is taken before the powders are consists 1n calcining the in edients for about an ,hour in any suitable rnace which is kept at a temperature of about 1000 C.

I'claim: 1. A process of producing synthetic sapphires consisting. in causin' compounds of aluminium, iron and titanium to be sub- One can start" put into receptacle B. This step.

eeaaao jected to a flame, in convertin the same to alumina, oxid of iron and oxi of-titanium and in fusing said alumina, oxid of iron and oxid of titanium together.

2. A process of producing synthetic sapphires consisting in causing alumina oxid of non and oxid of titanium to be fused together.

phires consisting 1n causing an aluminium compound, an iron compound and a titanium compound to be subjected to a flame, in reducing the same to alumina, oxid of iron and oxid of titanium and in fusing said alumina, oxid of iron and oxid of titanium to ether.

5. The process of producing synthetic sapphires, which consists in heating sulfate of aluminium, sulfate of iron, and sulfate of titanium until they are reduced to oxids and then continuing the heating to the fusing point.

- 6. A process ,of producing synthetic sapphires consisting in first calcinin a compound of aluminium, a compoun of iron and a compound of titanium and then fusing them together.

7. A process of producing synthetic sapphires consisting in causing a compound of aluminium, a compound of iron and a compound oftitanium to be fused together.

8. The process. of producing synthetic precious stones whichconsists 1n preparing a mixture containing aluminium, 1ron and titanium in proportions adapted to reduce a sapphire containing substantial y 98% aluminium oxid, 1.5% iron oxid, 0.5% titanium oxid; and in subjecting said mix,- ture to a temperature suitable for produc; ing said oxids in the form desired, substantially as described.

9. A composition of matter adapted t0 produce sapphires and containing aluminium, iron and titanium in such proportions that when heated to a suitable temperature there will be produced a mass containing substantially 98% aluminium oxid, 1.5% iron oxid, and 0.5% titanium oxid, substantially as described.

. iueusrr VIOTOR'LOUIS transmit.

Witnesses: LOUIS RINNY,

DEAN B. Mason. 

